Apparent longitude
 | This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (March 2026) |
Apparent longitude is celestial longitude corrected for aberration and nutation as opposed to mean longitude.
Apparent longitude is used in the definition of equinox and solstice. At equinox, the apparent geocentric celestial longitude of the Sun is 0° or 180°. At solstice, it is equal to 90° or 270°. This does not match up to declination exactly zero or declination extreme value because the celestial latitude of the Sun is (less than 1.2 arcseconds but) not zero.
Sources
[edit]- United States Naval Observatory. Astronomical Almanac Glossary Chapter.
- Meeus, Jean. Astronomical Algorithms (Second ed.).
 | This astronomy-related article is a stub. You can help Wikipedia by adding missing information. |